tag:blogger.com,1999:blog-21402852.post4778347282662759320..comments2018-03-18T08:24:05.978+10:00Comments on The NXT STEP is EV3 - LEGO® MINDSTORMS® Blog: Particle filter with NXTAsha Seshannoreply@blogger.comBlogger4125tag:blogger.com,1999:blog-21402852.post-28663410708272516902007-12-14T07:06:00.000+10:002007-12-14T07:06:00.000+10:00Yes the NXT motors are very accurate, but as you s...Yes the NXT motors are very accurate, but as you say they require carefull building and the initial setup is crucial. <BR/><BR/>Where something like this comes in handy is when you are not sure of the condition you will encounter. By taking in information from a variety of sensors, you can get a 'better' picture of exactly what your robot is doing.<BR/><BR/>Particle filters are just one way of combining several different types of data into meaningful information<BR/><BR/>damoDamien Keehttps://www.blogger.com/profile/05396900452353669763noreply@blogger.comtag:blogger.com,1999:blog-21402852.post-16623083404438750132007-12-13T23:28:00.000+10:002007-12-13T23:28:00.000+10:00While I agree with you that such problems can be "...While I agree with you that such problems can be "minimized & dealt with", you usually do not have such total control over the environment as in FLL. Carpet, edges, bumps, etc., limit real world performance far more in most situations.<BR/><BR/>As to a FLL robot being "Accurate to better than 1mm linearly and 0.5 degrees rotationally"... well, I'd be curious to know exactly what you mean by these. For instance, "1mm linearly" has very little meaning to me - does that mean it can navigate to the same location, 10 meters away from the start point, and end up with a pointer in a circle 2mm in diameter in 98 tries out of 100? Or does it mean that in one test, the robot stopped within 1 mm of a line located 10 cm away from the start? Likewise for angular position, how did you measure that small and angle (I survey caves, and the equipment used only reads to the half degree... and the actual accuracy is much less, usually around +/- 2 degrees). Was that an error in the way the robot moved, or in the starting positions? Etc.<BR/><BR/>-- <BR/>Brian DavisBrian Davishttps://www.blogger.com/profile/18309361462316728701noreply@blogger.comtag:blogger.com,1999:blog-21402852.post-31613217326523280242007-12-13T22:20:00.000+10:002007-12-13T22:20:00.000+10:00"The big problem stems from the fact that the robo..."The big problem stems from the fact that the robot's wheels have to slip to make the robot move (a fact of physics), so careful measurement of the motors' rotation sensors is not going to help you."<BR/><BR/>The wheels may have to slip but exactly how much is the slip over distance traveled. If proper programming and construction techniques are utilized this slippage can be minimized and dealt with. My FLL team's robot is accurate to better than 1mm linearly and .5 degrees rotationally - tested physically and programmatically.<BR/><BR/>JoshJoshua Heinzlhttps://www.blogger.com/profile/14430903355164751820noreply@blogger.comtag:blogger.com,1999:blog-21402852.post-74249171167613486662007-12-13T19:07:00.000+10:002007-12-13T19:07:00.000+10:00Thank you for the link - it is really interesting....Thank you for the link - it is really interesting.<BR/><BR/>I also read the stuff he is doing with some of the Mindsensors hardware - including the newly released camera sensor.BlueToothKiwihttps://www.blogger.com/profile/05509100068326737423noreply@blogger.com